CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Statement of Financial Position [Abstract]
Allowance for loan losses	$ 199,720	$ 203,753
Goodwill	$ 414,722	$ 411,360
Preferred stock, par value (in dollars per share)	$ 1.00	$ 1.00
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	300,000	300,000
Preferred stock, shares outstanding (in shares)	300,000	300,000
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	154,408,001	154,007,429
Common stock, shares outstanding (in shares)	78,186,520	81,220,269
Treasury stock, shares (in shares)	76,221,481	72,787,160